Method of and apparatus for fumigation



June 10, 1924.

F. W. BRAUN ET AL METHOD OF AND APPARATUS FOR FUMIGATION Filed July 17 INVENTOR mr/l' Emu r, 44

I Patented June 10, I924.

1,497,428. ran STATE PATEN. OFFlCE.

FREDERICK w. BRAUN, OF PASADENA, AND JOSEPH J). NEUIZS, or 'Los ANGELE S, CALI- FORNIA, ASSIGNORS TO CALIFORNIA CYANIDE COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

'METHOD'OF AND APPARATUS FOR EUMIGATIOW.

To'aZZ whom. c't may concern:

Be it known that we, FREDERICK W. BRAUN, a citizen of the United States, residin at Pasadena, in the county of Los An e es, State of California, and JosEPH D. nuns, a citizen of the United States residing at Los Angeles, in the county of Los Angeles, State of California, have invented certain new and useful Improvements in "Methods of-and Apparatus for Fumigation; and we do-hereby declare the following to be a full, clear, and exact description of the invention, such as Will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to fumigation and particularly to a method of and apparatus for safely generating and handling poisonous gases which are utilized in destroying insects.

'Hydrocyanic acid .gas is an effective and economical lethal agent for the destruction of insect pests and with reasonable care in handling it may be used without danger.

as A method of and apparatus for utilizing it especially in the fumigation of vegetation has been developed. The hydrocyanic acid is stored as a liquid in' portable containers.

Measured quantities of the liquid are delivered from, the container to a vaporizer wherein theliquid is converted into as.

The gas is then delivered through a flexible hose to the interior of a tent or other enclosure which surrou' ds the vegetation to be treated. When the reatment is completed the hose is withdrawn and placed beneath another tent.

In'conducting fumigation as described it has been observed that after the dose of h e0 drooyanic acid has been vaporized and t e hose is withdrawn from the tent, occasional ufisof gas emerge from the end thereof.

his gas is apparently produced by aftergeneration of some small part of the liquid as which remains in the vaporizer and connections. As thelgas is very poisonous it is desirable to eliminate all traces thereof from the vaporizer and hose before the latter' iswithdrawn from the tent. By so do- 60 in the possibility of accidents due to inha ation of the gas is averted.

It is the object therefore of the present invention to safeguard the use of hydrocyanic acid by purging the vaporizer and hose of poisonous gas after each application. Further objects and advantages of the invention will be apparent as it is better understood by reference to the following specification and accompanying drawing in which the figure diagrammatically illustrates an apparatus'which may be utilized for the accomplishment of the stated objects.

We have discovered that the elimination of the poisonousfgas may be accomplished in a simple and e ective manner by delivering a small quantity of a non-poisonous liquid such as water to the vaporizer as soon as the charge of liquid hydrocyanic acid has been converted into' as and before the hose is withdrawn from t e tent. The liquid is immediately vaporized and sweeps throu h the connections to the end of the hose.

as from the apparatus and the hose may e withdrawn thereafter and handled with- Referring to the drawing for. a more detailed explanation of the invention and its mode of application, 5 indicates a container for theliquid to be vaporized, for example hydroc anic acid or a solution or mixture thereo with water. The liquid is withdrawn through an outlet 6 and passes through a pipe 7 to av measuring pump 8 which may be of any suitable form and construction. The function of the pump 8 is to withdraw a predetermined volume of the liquid from the tank and to deliver it through pipes 9 and 10 to a vaporizer coil 11. check valve 12 is provided toprevent the return of liquid or gas to the pump and as an additional precaution the pipe 10 is preferably provided with a 100 13. A heat-insulatin flange 14: is disposed between the coil 11 an the ipe 10 to prevent transfer of heat by comfhction through the pipe connections. The coil 11 may be heated in any suitable manner, for example, by plac ing it in a combustion chamber inwhich the exhaust gases from an internal combustion engine are burned. The end. ofthe- T e vapor forces every trace of hydrocyanic acid coil 11 is connected to a flexible hose 15 through which the gas is delivered to a tent or enclosur (not shown).

In carrying out the present invention a tank 16 is provided which is adapted to contain a quantity of water or other non-poisonous liquid. A pump 17 is connected by a pipe 18 to the tank 16 and a pipe 19 deivers the liquid from the pump through a check valve 20 to'the pipe 10.

V In conducting the operation the end of the hose is disposed beneath the tent or within the enclosure to be fumigated; The

coil 11 is" heated as hereinbefore descr'bed and the pump 8 is set to measure the desired quantity of liquid from the tank '5. The pump 8 is then actuated to deliver the liquid to the coil 11 where it is vaporized. The ressure generated causes the gas to fiow t rou h the hose 15 into the tent or enclosure. Vhen sufficient time has elapsed to permit vaporization of the poisonous liquid the pump 17 is actuated to forcea quantity of water through the pipe 19. All of the poisonous liquid in the pipe -10-is carried over into the coil 11 and the large volume of steam generated by vaporization of the water thoroughly. urges the system of poisonous gas, all 0? w ich, together wlth the steam, is delivered from the hose 15 to the tent or enclosure. The hose may be withdrawn with safet and transferred to the next enclosure. 'l he purging might be accomplished likewise by introducing a gas or a vapor produced externally thereof to the vaporizer coil. The introduction of liquid as described is, however, simpler as it avoids the necessity of maintaining a supplgrof gas or vapor.

ariousj changes may be made in the details ofthe structure and the mode of operation as described without departing from the invention or' sacrificing any .of the advantages thereof. V

" We claim 1. A method of safeguardingthe genera tion and delive of poisonous gases in fumigation, whic comprises" gasifyin a poisonous li uid by the application of eat, conducting t e resulting gas to an enclosure, and pur 'ng the gasifying and conducting means 0 the poisonous as b conducting a non-poisonous vapor there's rough to the same enclosure. 1

2. A method of safeguarding the generamemes tion and deliver of poisonous gases in fumigation, whic comprises gasifying a poisonous 1i uid by the application of cat, conducting t e resulting gas to an enclosure and pur mg the gasifying and conducting means 0 the poisonous gas by introducing a non-poisonous liquid thereto,vaporizing the liquid therein and conducting the vapor to the same enclosure.

3. A method of safeguarding the generation and delivery of gaseous hydrocyanic acid, which comprises gasifyin a liquid containing hydroc anic acid by t e appl1cation of heat, con noting the resultin gas to an enclosure and pur ing the gasi ymg and conducting means of the poisonous gas by introducing water thereto, vaporizing the water therein and conducting the steam to the same enclosure.

4. In an apparatus for safeguarding the generation and deliver of poisonous gases in fumigation, the com ination of a vaporizer, means for delivering poisonous liquid thereto, a conductor to deliver the gas formed in the vaporizer to an enclosure and means for delivering a non-poisonous liquid to the vaporizer whereby the vaporizer andconductor are purged of the poisonous gas.

5. In an ap aratus for safeguarding the generation and delivery of 01SOI10l1S gases 1n fumigation, the combination of a vaporizer, means for delivering poisonous liquid thereto, a conductor to eliver the gas formed in the vaporizer to an enclosure, a tank for nonoisonous liquid and means for delivering t anon-poisonous li uid from the tank to the vaporizer whereb t e vaporizer and conductor are purged o the poisonous as.

6. 11 an ap aratus for safeguarding the generation an deliver of poisonous gases in fumigation, the com inat1on of a vaporizer, means for delivering oisonous liquid thereto, a conductor to eliver the gas formed in the vaporizer to an enclosure, a tank for non-poisonous liquid and means, including a pum for del vering the nonpoisonous liquid rom the tank to the vapor- .ixer whereby ,the vaporizer and conductor are purged of the polsonous as.

In testimony whereof we a x our signatu es. r FREDERICK W. BRAUN.

JOSEPH D. NEULS. 

